If you’re still plagued by having to use Ruby 1.9.3 and you may be using, idk, Vagrant or any other type of testing environment, or just your own machine, you may have encountered the following error when installing either “debugger-ruby_core_source” or the “debugger-linecache” package.

This can particularly happen if you’re using RVM or other ruby version managers

Now, most stackoverflow answers and blogs will tell you to issue the following command:

Step 1: Install RVM and Ruby

Step 2: Fetch Ruby Source Code

Here comes the important part. INSTALL THE RUBY SOURCE CODE! This is the part NO ONE tells you. Here’s what you add right below that installation:

rvm fetch ruby-1.9.3-p484

Whoa, whoa, yep. That’s it. When your package tells you it can’t find vm_core, or that it can’t compile, this is probably the culprit. So make sure you fetch the source code.

Step 3: Install Debugger-Ruby-Core_Source first

If it wasn’t enough, we’ll install this nifty package first. This was the original fix on ruby’s github issue page. It works, some of the time, in some instances, sometimes. Let’s be sure we got it covered.